Introduction

The reproductive System of cockroaches is why we see this insect roaming in our kitchens. Even with simple anatomy and small size, cockroaches have a well-built reproductive system. Cockroaches reproduce by sexual means. There is a difference between  female and male reproductive systems of cockroach. Cockroaches belong to the largest class of Insecta. Also, they are part of the largest Animal phylum, which experts call Phylum Arthropoda. The reproductive system of cockroaches is responsible for reproduction in this insect’s male and female genders. 

Reproductive System of Male Cockroach

The cockroach male reproductive system includes  testes, vasa deferentia,ejaculatory duct, mushroom-shaped utricular gland, phallic gland, and external cockroach genitalia.

• Testes: These refer to massive elongated structures. Testes extend in a longitudinal direction such that one is on each side of the abdomen. There are around 3-4 interconnected lobes in the testes
• Vasa deferentia: This is a short, delicate duct that extends from each testis. The duct goes on to about the hind end of the cockroach’s body and opens into ejaculatory duct 
• Ejaculatory duct: This is a duct that is contractile and elongated in nature. Moreover, the ejaculatory duct has a pear-shaped appearance. This duct extends back from the vasa deferentia junction to the hind end of cockroach’s body
• Mushroom-shaped or utricular gland: This is an accessory gland that is large in size and its color  is whitish.  The location of the utricular gland is at the junction of the ejaculatory duct and vasa deferentia. Its formation comprises three small sacs- long tubules or Utriculi majors, tiny tubules or Utriculi breviores, and small, bulb-like seminal vesicles

• Phallic or conglobate gland: This is a sac-like accessory gland that is flattened and long. Its appearance is club-shaped. The location of this gland is beneath the utricular gland
• External genitalia or male gonapophyses (Phallomeres): This refers to three asymmetrical and chitinous structures; left phallomeres, right phallomeres and the ventral phallomeres. The male gonapophyses form the male cockroach’s external genitalia

Reproductive System of Female Cockroach

The various parts of the cockroach female reproductive system are: ovaries, oviducts, vagina, gynatrium, collateral glands, Spermatheca, and gonapophyses.

• Ovaries: These are organs that are elongated and extend laterally. These ovaries are arranged one on each side of the abdomen
• Oviducts: This is a muscular, thick, and small part of the female cockroach reproductive system. It is formed by joining together the eight ovarioles pedicels of an ovary
• Vagina: This is a thick and median oviduct formed by the joining together of the two oviducts
• Genital pouch or gynatrium: Vagina opens in a genital pouch which is formed by fusion of three abdominal sterna. The 7th sternite becomes boat-shaped and it forms the floor of  pouch. The 8th and 9th sternites result in the formation of the genital pouch roof and sides. The division of the genital pouch takes place into two chambers, one in front and the other at the back. The chamber in the front is the genital chamber and the chamber that is behind is the oothecal chamber
• Collateral glands: These are a pair of accessory reproductive glands that are white. Also, they are characterized by being highly branched, and their location is dorsal to the genital pouch. The left gland size is larger than the right gland size 
• Spermatheca: These are a pair of small structures which are located nearby collateral glands. The size of the left spermatheca is larger than the size of the pyriform sac. The right spermatheca is similar to a narrow duct
• External genitalia or gonapophyses: The external genitalia of the female cockroach refers to pairs of chitinous processes. It hangs from the roof of oothecal chamber into the cavity of this chamber

Functioning of Reproductive System of Cockroach

It functions as follows:

• The formation of the sperms takes place in the testes of a young male cockroach. When the male cockroach is fully grown, this sperm formation slows down. Afterwards, the size of the testes gets comparatively more minor
• Vasa deferentia in male cockroaches conduct mature sperms into the seminal vesicles for storage. Here, the gluing of the sperms takes place together into a spermatophore, which is like a large mass
• The discharge from a seminal vesicle in a male cockroach occurs in the ejaculatory duct. A milky secretion of long tubules invests the spermatophore
• During copulation, spermatophore deposition occurs near the spermathecal pore in female cockroaches. This takes place by the gonapophyses of male cockroaches. After the migration of spermatheca, the spermatophore wall shall be dropped
• Each ovariole is a female cockroach that forms one single mature ovum at a time. Afterward, descending sixteen eggs takes place into the genital chamber. As they are laid, sperms fertilize them. The ejaculation of sperms takes place simultaneously from spermathecae
• The fertilised eggs become hardened by collateral glands secretion in female cockroaches. The formation of the ootheca happens after the fertilized eggs are hardened 

Conclusion

Cockroach has a well-built reproductive system despite their simple anatomy and small size. Male and female reproductive system differ in their structure and are highly specialised in their functioning.